Beginner question regarding plugins in WebGL build

Hello,

for my current Unity Project, I want to include the Emotiv device as possible input.
This device needs two plugins to work. One is compiled by myself (as a dll in a win64 environment) and one is precompiled for win64, win86, linux64 and arm.
Right now I have all of them included in my Project.
My understanding of dll and plugins is quite poor… I guess you can only use a native plugin on the system where you compiled it. But I also read, that for WebGL Unity will translate the dll to work in a browser.

Can I use both of the win64 dlls for my WebGL Project and they will also work on a mac?

that’s true for Managed Dlls, not for native ones.
However, what you can do on WebGL, that you can’t on other Unity platforms, is to add the c/c++ sources to your project and they will be compiled into the final build. See manual for more information.

Thank you for the answer.
I have only the source code of the self compiled Dll available. That I included now in my project.
The other Dll I included based on the specific build but excluded WebGL now from every Dll in the project.
Still when I try to build the Project. I get this error:

Images from my Plugin Settings

Can you help me what I did wrong?
To restart the Editor does not help (maybe the changes were not yet loaded)

I found the solution. Not sure if that is a Unity Bug or I did something wrong here, but I think it is an Unity bug after I searched for a solution for a while and noticed, that this issue is present a lot.
Fix for plugin collision in WebGL:
Make sure that Any Platform is false (unchecked) and then exclude WebGL from one or both Plugins (I did both).
Maybe it is also possible to set Any Platform true and do the opposite.
I assume that you only have to be consistent. If some are true and some are false there will or could be this conflict.

Thanks for the update. What version of Unity are you using?

No Problem. Hope it helps.
I am using Unity 5.5.1f1